Help with query_posts function

The query_posts() function is almost wholly unnecessary and is discouraged in favor of WP_Query(). That being said we can look at the WP_Query() docs as they’re almost the same.

The cat parameter accepts either a comma separated string or integer. In this case we can use:

query_posts( array(
    'cat' => 1,
    'posts_per_page' => '8',
    'post__not_in' => $do_not_duplicate,
    'ignore_sticky_posts' => 1
) );